Study on Protective Effects of Astragaloside IV and Danshensu on Cardiac Function Against Myocardial Ischemia in Rats

OBJECTIVE To study the protective effects of astragaloside IV(AST) and danshensu on cardiac function in rats with myocardial ischemia and its potential mechanisms. METHODS Myocardial ischemia(MI) was induced by permanent ligation of the left anterior descending coronary artery in rats. AST and sodium danshensu(DSS) were administered intragastricly for 28 d, and cardiac function (ejection fraction, EF%; fractional shortening, FS%) was evaluated by echocardiography and ECG ST segment change. Masson staining was applied to evaluate the degree of myocardial fibrosis. 7 d post-MI, AST and DSS were given at low, medium and high doses (20, 40, 80 mg·kg^-1) both alone and in combination, and trimetazidine(TMZ) was used as control to detect the serum levels of NEFA and glucose. Heart weight/body weight ratios(HW/BW) were calculated to evaluate ischemic myocardial injury. The myocardial histopathology was further evaluated by HE staining. RESULTS Compared with the model group, 40 mg·kg^-1 AST and DSS significantly increased left ventricular EF% and FS%(P<0.01), and reduced the degree of myocardial fibrosis in the infarct myocardium. 40mg·kg^-1 DSS showed significant anti-myocardial fibrosis effect (P<0.05). 7 d post-MI, 10 mg·kg^-1 TMZ inhibited serum NEFA level and increased serum glucose; the combined administration of AST and DSS(AD group) further down-regulated serum NEFA level comparing with their single administration. AD i.g. further raised serum glucose levels, while 80 mg·kg^-1 AST and DSS i.g. alone decreased serum glucose levels comparing with the sham level. The HW/BW in the MI 7 d group were significantly higher than that in the sham group(P<0.05), which could be significantly reversed in each treatment group with different doses of AST and DSS. HE staining showed a large number of inflammatory cell infiltration in ischemic myocardium, together with disordered arrangement of myocardial cells and edema. AST and DSS i.g. for 7 d could effectively alleviate the above phenomena. CONCLUSION AST and DSS can protect ischemic myocardium and improve cardiac function at 7 and 28 d post MI in rats. The protective effects of the two components against ischemic myocardial injury and cardiac function improvement may be associated with the regulation of glucose and lipid metabolism, anti-inflammation and anti-myocardial fibrosis in ischemic myocardium.